public/cisa/exchange/Test-MtCisaEmailFilterAlternative.ps1

<#
.SYNOPSIS
    Placeholder
 
.DESCRIPTION
    Alternatively chosen filtering solutions SHOULD offer services comparable to Microsoft Defender's Common Attachment Filter.
 
.EXAMPLE
    Test-MtCisaEmailFilterAlternative
 
    Always returns null
 
.LINK
    https://mycorp.dev/docs/commands/Test-MtCisaEmailFilterAlternative
#>

function Test-MtCisaEmailFilterAlternative {
    [CmdletBinding()]
    [OutputType([bool])]
    param()

    if (!(Test-MtConnection ExchangeOnline)) {
        Add-MtTestResultDetail -SkippedBecause NotConnectedExchange
        return $null
    } elseif (!(Test-MtConnection SecurityCompliance)) {
        Add-MtTestResultDetail -SkippedBecause NotConnectedSecurityCompliance
        return $null
    } elseif("Eop" -in (Get-MtLicenseInformation -Product Eop)) {
        Add-MtTestResultDetail -SkippedBecause Custom -SkippedCustomReason "Tenant is licensed for Exchange Online Protection, an alternative mail filter is not needed."
        return $null
    } else {
        Add-MtTestResultDetail -SkippedBecause Custom -SkippedCustomReason "Tenant is not licensed for Exchange Online Protection and there is no implementation to check for alternate mail filters available."
        return $null
    }
}